Louis Ignarro: I think the best thing that makes science exciting is that you have the opportunity to think about important questions in science.  Whether it’s science, technology, medicine, chemistry, whatever it is, you have the opportunity to think about important and exciting questions.  You have the opportunity to then try to answer those questions.  And it’s up to you.  In other words, everything was up to me.  So everything is up to you.  You can design the experiments.  You test the hypothesis.  You look at the data.  You draw the conclusions.  And then you go from there.  And the greatest thing about all of this is when you’re able to answer a question satisfactorily, then you’ve made an important contribution to humankind.  I said, “Even if it’s not an important contribution to humankind, even if you’ve answered your own question satisfactorily and you could publish it somewhere,” I said, “that’s very gratifying and that’s a great reward in life,” because it’s one profession where you could have a lot of those rewards, but you do have to work hard.